Cartesian diver toy



Allg. 8, 1967 E. LoDRlcK 3,334,439

CARTESIAN DIVER TOY Filed NOV. 20, 1964 6 Sheets-Sheet l Aug- 8 1967 L.. E. LoDRlcK 3,334,439

CARTESIAN DIVER TOY Filed Nov. 20, 1964 6 Sheets-Sheet 2 f7@ 7 Z6 Z6 INVENTOR. Haney/d Zw/e0 ope/cse Allg- 8 1967 L. E. LODRICK CARTESIAN DIVER TOY 5 Sheets-Sheet 3 Filed Nov. 20, 1964 INVENTOR 4 ,9a/e @V65 .60W/2e@ 00E/@fe A118- 8 1967 l.. E. L oDRlcK CARTESIAN DIVER TOY 6 Sheets-Sheet 4 Filed Nov. 20, 1964 5% m Nw kum INVENTOR.

Aug- 8 1967 L. E. L oDRlcK CARTESIAN DIVER TOY 6 Sheets-Sh1eet 5 Filed Nov. 20, 1964 AVII//l//f//l mM\ NNY @MY INVENTOR waff/V56 bwa/fw vae/cf Aug- 8, 1967 L.. E. LODRICK CARTESIAN DIVER TOY 6 Sheets-Sheet e Filed NOV. 20, 1964 I N VEN TOR.

waff/V46 Zwaag maf/efe United States Patent O 3,334,439 CARTESIAN DIVER TOY Lawrence Edward Lodrick, Hazel Park, Mich. (3364 Harvard, Royal Oak, Mich. 48072) Filed Nov. 20, 1964, Ser. No. 412,744 3 Claims. (Cl. 46-92) This invention pertains to toys in general and more specifically to the Cartesian diver toy.

Broadly speaking, Cartesian diver toys are well known in the art and consist of a simulated aquatic figure which is caused to rise and sink in a liquid filled chamber by varying the pressure of the liquid. Toys of this nature have been found not only to be intriguing to both children and adults but also to possess certain benefits as a visual educational device for children.

A broad object of the invention is to provide a Cartesian diver toy which has certain novel features of construction and operation that enhance its interest to children and its actual play value.

A more specic object of the invention is to provide a Cartesian toy of the character described in which a simulated aquatic gure such as a diver is maneuvered by the operator through a predetermined path.

Another object of the invention is to provide a Cartesian diver toy of the character described in which the predetermined path is of the maze effect where skill is required by the operator to maneuver the Cartesian diver along said predetermined path.

Yet another object ofthe invention is to provide the aquatic figure with resultant horizontal component movement achieved through the use of angled planes.

A further object of the invention is to provide features to enhance its imaginative qualities to allow a child great freedom of imagination. This is accomplished by supplying the invention with simulated dials and said dials being operated with linkages which are in turn connected to the pressure operative mechanism.

Yet a further object of the invention is to provide a Cartesian diver aquatic figure that will prevent entry of the liquid into the said ligure.

A still further object of the invention is to provide a Cartesian diver toy of the character described possessing various novel `features of construction, appearance and use which result in a toy possessing greatly increased entertainment, educational and actual play value.

Other objects, advantages, and features of the invention will become readily apparent as the description proceeds.

Briefly stated, the objects of the invention are attained by the provision of a Cartesian diver toy equipped with a transparent chamber lled with liquid, such as water. Also inside the chamber are transparent planes which depict a predetermined path along which the aquatic figure travels.

Each of said predetermined path arrangements are in the form of a three dimensional maze or the transparent chamber itself may form the predetermined path. Resultant horizontal component motion is achieved by sliding along said planes.

The pressure mechanism, which gives the aquatic ligure motion, is in turn linked to simulated dials, of pressure and depth reading, in such a manner as to allow the proper proportion between readings.

Also the use of nearly identical planes of sections in the construction of the said predetermined path in the toy are a means to lower the manufacturing costs.

The toy possesses various other novel features of design and use which will become readily apparent as the description proceeds.

The invention may be best understood from the followice ing detailed description thereof, taken in connection with the annexed drawings, wherein:

FIG. 1 is a front elevational view of the present Cartesian diver toy;

FIG. 2 is a side elevational View of the aquatic figure;

FIG. 3 is an enlarged front elevational view of the aquatic ligure;

FIG. 4 is an enlarged side elevational view of the aquatic figure;

FIG. 5 is an enlarged back elevational View of the aquatic figure;

FIG. 6 is an enlarged partial section along line 6-6 of FIG. 5;

FIG. 7 is a partial section along line 7-7 of FIG. 2;

FIG. 8 is a section along line 8--8 of FIG. 7;

FIG. 9 is a section along line 9-9 of FIG. 7;

FIG. 10 is a section along line 10e-10 of FIG. 7;

FIG. 11 is a section along line 11-11 of FIG. 7;

FIG. 12 is a partial section along line 7-7 of FIG. 2;

FIG. 13 is a partial section along line 13-13 of FIG. 7;

FIG. 14 is a partial section along line 14-14 of FIG. 2;

FIG. l5 is a partial section along line 15-15 of FIG. 14;

FIG. 16 is a front elevational view of a second embodiment of the Cartesian diver toy;

FIG. 17 is a section along line 17-17 of FIG. 16;

FIG. 18 is a section along line 18-18 of FIG. 17;

FIG. 19 is a front elevational view of the constant plane configuration used in FIG. 18;

FIG. 20 is a front elevational view of a third embodiment of the Cartesian diver toy;

FIG. 21 is a side elevational view of the third embodiment of the Cartesian diver toy;

FIG. 22 is a section along line 22-22 of FIG. 20;

FIG. 23 is an enlargement of the circled portion of FIG. 22.

Referring now to these drawings, the present Cartesian diver toy 24 will be seen to comprise a sealed hollow, circular, transparent chamber 25 supported on a base 26, with a front plate 26, on which is mounted two pressure lever handles 27 and 28 which will-be discussed later. Mounted within this panel 26 are also simulated -dials 29, Btl, 31, 32, and 33. On top of the chamber 25 is a boat 2S. Out of the top of chamber 25 protrudes an externally threaded transparent tube 34 on which is threaded a removable closure or cap 35. This tube 34 and cap 35 allow removal of the aquatic figure 36 and presents an easily accessible point to fill the chamber 25 with liquid 37, such as water.

The aquatic figure 36 being shown as a diver, but may be a sh, diving bell, aquanaut or the like, is made of plastic and hollow in its upper portion. It also has a rubber diaphragm 38 glued to the diver 36 around its periphery as shown at points 39 and 40. This diaphragm 38 is made of rubber substance such as balloon rubber to allow the necessary stretch characteristics. The diver 36 is also designed and constructed to prevent any ofthe liquid from getting into its chamber 41. When the pressure is increased diaphragm 38 is forced into the diver 36 and thus the cavity is partially filled. The buoyancy is thus varied.

In use of the toy the aquatic figure is brought down through the predetermined path by increasing the pressure which is achieved through the use of the pressure varying mechanism. When said figure can proceed no further down the predetermined path the pressure is released and said gure rises contained by said predetermined path until more pressure is required to achieve further motion.

A novel feature of the invention resides in the base 26 and its contents of pressure varying mechanism, simulated dials and linkages thereof.

Two pressure hand grips 27 and 28 protrude out of the front plate 26 of base 26. A squeeze lever 84, inside each hand grip, when squeezed in, its extension 86 proceeds up in an arcing motion pushing compressor tube 87 upward through linkage members 88 and 89. Linkage members 88 and 89 must pivot at both ends due to the change from circular to straight line motion. Screws 90 and 91 provide this rotation of extension 86. A rod 98 is passed through hole 96 of flange 97 which holds linkage members 88 and 89 in place on tube 87. As compressor tube 87 is moved upward, the rubber bulb 99 is squeezed into a figuratively smaller shape and thus achieves the necessary pressure to cause the diver 36 to descend.

The rubber bulb 99 is of such a size as to lill that portion of the compressor tube which resides below the connection of rubber bulb 99 and pressure inlet tube 100 which is attached to the bottom wall 74 of the chamber 25 at such an angle as to facilitate the proper clearance between pressure tube 87 and base wall 26 which is said bases front wall. An inlet hole 167 is provided within inlet tube 100 in bottom wall 74 of chamber 25. Wrapping a wire 101 around the rubber bulb 99 and inserting both behind the flange on tube 100 accomplishes the attachment of bulb 99 on tube 100. The ends of wire 101 being behind the flange of tube 100 are crimped or twisted together to tighten joint 102 suciently to prevent pressure and liquid leakage. The entire joint 102 has a smaller diameter than tube 100s inner diameter to prevent drag on the movement of tube 87 as can be seen in FIG. 15.

Two external flanges 104 and 105 are attached to compression tube 87. Linkage arms 106 and 107 are connected to anges 104 and 105 respectively. The action of this linkage will be best understood if only one linkage is discussed because they are geometric opposites. The attachment of linkage arm 106 to flange 104 is through slot 108 and arm 106 is allowed to rotate around shoulder screw 109. Peg 110 protrudes from the front wall 26 of base 26 and supports pivot screw 111 which passes through hole 112 in linkage arm 106. As can bev seen from FIG. 14 arm 106 is in the form of an H. While in motion screw 111 is stationary and shoulder screw 109 approaches it. A third pivot point is at the end of linkage arm 106, which is in another slot 115 in arm 106 with a large head rivet 116 going through slot 115 and attaching to arm 117. These slots 108 and 115 are necessary to allow shoulder screw 109 and rivet 116 to approach each other. A second peg 118 protrudes from wall 26 to which is attached a spring 119. This spring 119 is also attached to arm 106 and is necessary only to insure arm 117 returning to its original position. This is necessary because arm 117 is directly connected to the pointer arrow 120 of simulated dial 30 which is a gauge indicating a simulated depth reading and a zero start reading is preferred. Simulated dial 29, also actuated in the same manner mentioned previously, is a gauge indicating a pressure reading. Simulated dial 32 is an actual timer such as a stop watch so the toy can be used as a game to show each player how fast he maneuvered diver 36 through the predetermined path. Simulated dial 31 is a dial face used only to finish off the symmetry of base 26. The large circular dial 33 is a simulated radar screen to add to the imaginative quality presented by the toy.

Another novel feature of the present Cartesian diver toy is the defining of a predetermined path for the diver 36 to follow. This description thereof will best be understood through the description of the divers motion through the toy as shown in FIG. 7, FIG. 8, FIG. 9, FIG. 10, and FIG. 11. The diver 36 at start position 55, actuated by an increase in pressure, utilizing the pressure varying mechanism mentioned previously, descends out of tube 34 usually in a straight line to the transparent plane 42, and contacts it at point 43. The plane 42 has a slope of approximately 30 degrees which enables the diver 36 to slide down to the edge 44 then drop down to plane 45 which is supported from plane 42 by the transparent support and diver retainer 46 which is glued or fastened to each.

Plane 45 has the same approximate 30-degree slope as plane 42 and is compounded on an approximate 20-degree slope to allow the diver to slide to position 47. When the diver 36 reaches position 47 said diver 36 can not proceed in any direction but an ascending direction. To achieve this, the pressure is released through the pressure adjustment means and diver 36 ascends to contact plane 48 which is supported by the retainer support 49. The plane 48 is also at an angle of approximately 30 degrees and the diver 36 ascends plane 48 conned to the path of the plane by support 49 and the wall of the chamber 25. The diver proceeds up plane 48 to edge 50 and must be made to descend through opening 51. If this is not done the diver 36 will ascend up to plane 52, which is also at a slope of approximately 3() degrees and the diver 36 proceeds up plane 52 to plane 53 which is a retainer at approximately 1() degrees to the vertical and fastened to plane 52 along joint 54. The resultant path dened by these two planes brings diver 36 back to its original position 55. If the toy is operated correctly the diver 36 proceeds through opening 51 and contacts transparent plane 56 which is at a slope of approximately 30 degrees but sloping in an alternate direction than plane 42. The side retainers 57 and 58 guide the diver 36 along an S-shaped path 59 and the retainers are positioned and attached to plane 56 as the allow all resultant angles to be at least l5 degrees along this path 59 to insure the diver 36 overcoming retarding friction forces. When the diver reaches edge 60 and opening 61 it then drops down to plane 62 and contacts it at point 63.

The diver 36 proceeds along plane 62 which has a slope of approximately 30 degrees also sloping in an alternate direction than the previously mentioned planes, until it reaches edge 65. Then the diver 36 must proceed down plane 64 which has a slope of approximately 80 degrees and is attached to plane 62 at edge 65. The diver 36 descends down plane 64 until it reaches plane 66 of slope approximately 30 degrees and in turn moves down plane 66 until it can go no farther and is against the wall of chamber 25. Plane 66 is also attached to plane 64 along joint 67. Now the pressure must again be released through the use'of the pressure varying mechanism to cause the diver 36 to ascend in its usual vertical path to plane 68 which is inclined in such a manner as to keep diver 36 moving up and along the wall of chamber 25. Support 162 holds plane 68 in place. The resultant angle of plane 68 is approximately 20 to 30 degrees. When diver 36 reaches point 69 the pressure must be made to increase causing the diver to descend to Contact plane 70 which has a slope of 60 degrees from the horizontal. If this is not done the diver 36 will ascend to the under side of plane 56 and proceed up plane 56 until it can go no farther and is against chamber wall 25. Then from this point diver 36 must be brought again down to plane 62, etc. If the toy is operated correctly plane 70 acts as a guide and retainer to bring diver 36 under the extension 71 of plane 62. Again pressure must be released and the diver moves up extension 71 and then the underside `of plane 62 until it clears plane 66 or until it rests against the wall of chamber 25. At this time the pressure must be increased causing the diver 36 to descend and contact plane 76. The diver 36 proceeds down plane 76 which is at an angle of approximately 30 degrees until it reaches plane 73 and the direction of diver 36 is changed, diver 36 then proceeds down plane 73 at a slope of approximately 30 degrees until it reaches the bottom 74 of chamber 25. At this position 75 the diver 36 is under plane 76 and can proceed no farther down. The pressure is released and the diver 36 ascends to contact the underside of plane 76 and moves up plane 76 in a straight line and at the slope of plane 76 until it contacts retainer plane 77, joined to plane 76 along joint 78. The resultant angle is approximately 20 degrees and the change in `direction of the diver 36 caused by plane 76 directs said diver 36 into opening 79 of return tube 80 at position 81. The pressure being released, the diver 36 ascends through the return tube 80 and out of opening 82 and ascends to contact plane 52 then proceeds up plane 52 until it contacts plane 53 and the combination of both planes guide diver 36 along the resultant path and angle mentioned previously until the diver 36 enters tube 34 and resumes start position 55. It can be seen that to achieve the above mentioned slope an elliptical plane of 6() degrees is employed in almost all cases and wherever feasible to standardize construction.

FIG. 12 shows a novel feature of the toy which is one of the possible arrangements of simulated sea life placed and glued on the planes of the predetermined path in such a manner as not to conict with the movement of the diver 36 through said predetermined path. This sea life can be and is arranged on the different levels according to the depth at which it is found. That is to say surface sea life is at the top and so on down until the bottom has attached to it simulated crawling sea creatures. This method of placement of the simulated sea life both educates the child as to different de-pths of sea life and enhances the beauty and imaginative stimulus of the toy. To

prevent the repetition of tracing Athe divers path mentioned previously assume all sea life is place so as not to conflict with the predetermined path of the diver 36 and only those planes to which the simulated sea life is attached and behind will be mentioned. A simulated plastic jellyfish 168 is `attached to plane 52. Several small iish 169 which represent a school of iish are glued on top of plane 48. A simulated angel fish 170 is fastened to retainer 49. Some seaweed 171 is glued on top -of plane 42 and a giant clam 172 with a pearl 173 inside of said clam is fastened between planes 42 and 45. Said clam 172 is partially beneath plane 42 to allow the diver 36 to pass over said clam 172. Simulated underwater vegetation 174 is fastened to plane 56, With said vegetation 174 placed outside of retainer walls 57 and 58. A few rocks 175 are intermittently placed at the base of the vegetation 174. Two barracudas 176 and 177 are also attached to retainer wall 58 amidst the vegetation 174. Simulated coral 178 and 179 is attached to the underside of planes 62 :and 66 respectively. A simulated deep sea bass 180 is also attached to the underside of plane 66. Simulated seaweed 163 is attached to the underside of plane 64. A simulated giant squid 181 is attached to the underside of plane 76, behind retainer 77. Simulated sea plants 182 are intermittently spaced and attached to plane 73. Rocks 164 and a simulated sea chest 161 rest on bottom 74. The liquid is absent in FIG. l2 to better show the simulated marine life placement.

Another embodiment of the invention is shown in FIGS. 16 through 18. This embodiment consists of a chamber 130 placed on base 26 with tube 34 and cap 35 protruding out of top 131 of chamber 130. Chamber 130 is of a rectangular shape as opposed to the circular shape of chamber 25. Chamber 130 is constructed of four transparent sheets glued together as shown in FIG. 17. Sides 133 and 134 are glued to front face 132, and back plate 135 is glued to sides 133 and 134. An alternative design of chamber 130 has back plate 135 and sides 133 and 134 opaque with a marine scene as mentioned previously on face 136 of back plate 135. The predetermined path for diver 36 is as shown in FIG. 18. This path is constructed in the form of a maze using, for manufacturing simplicity, a multiple placement of the identical Z-shaped section 137 with a few variations. These variations are that sides 138 and 139 of the standard section 137 are made shorter or longer as necessary placement dictates. The method of moving diver 36 through the predetermined path outlined in FIG. 18 is much Ithe same as previously mentioned. It must be noted however that during construction of said predetermined path point 140 must always be in front of point 141 as the diver 36 is designed to use straight line vertical motion when moving through the liquid and only the liquid. That is to say when the diver 36 reaches a resting point and can proceed no farther at that pressure setting, pressure must be changed so the gure ascends or descends to contact a sloped plane through the divers vertical path in said liquid.

Another novel feature of the toy is the construction and design shown in FIG. 20 through FIG. 23 which is the third embodiment 166 of said toy. In this instance the chamber 142 itself determines the predetermined path for the diver 36 to follow. The chamberl 142 is attached to liquid reservoir 143 which has an inlet tube 144 protruding out of it. On the end of inlet tube 144 is a rubber pressure bubble 145, attached to said tube in the manner mentioned previously.

A palm b-utton 146 is pressed and its extension 147 compresses rubber pressure bubble within housing 148. Base 149 supports the above mentioned parts and to hold chamber 142 a plastic brace 150 is supplied and is fastened to chamber 142 and base 149 in such a manner as to allow the toy to be put together by the operator.

The topmost portion 151 of the chamber is of circular cross section to allow external threading and permit clo. sure cap 152 to be 'screwed in place. AS can be seen in FIG. 20, there are air pockets which would be created when the chamber 142 is filled with liquid. To alleviate this problem, tie-in tubes 153, 154, 155, 156 and 157 are used and will allow the air which would be :trapped in these vertices of the chamber 142 to escape to the surface or top'151. The marine scene 153 shown in phantom in FIG. 20 and FIG. 21 can be in any configuration desired and can be constructed by the vacuum form process in such a manner as to allow portions of it to cover Ithe chamber 142 to hide said chambers path from the operator to necessitate skill to maneuver the driver 36 through the hidden portion of the predetermined path. This scene 158 is slipped down over chamber 142. FIG. 22 and FIG. 23 show one of the many possible chamber construction techniques, making said chamber in .two halves 159 and 160. To achieve ease of construction with an insured pressure seal, the joint of half 159 with half 160 is formed in the manner shown in FIG. 23.

It has been found that when tap water is used as the liquid element of the toy, bubbles form on the transparent pressure chambers inner surface. Also the use of distilled water or water that has heen boiled a few minutes eliminates this bubble formation.

While, in the preceding description, the invention has beeeu referred to as a toy it will be apparent that the invention also serves `as a unique visual educational device. Thus, the device may be used to acquaint a child with various forms of sea life. Moreover the desired uses of the toy acquaint the child with various physical laws such as the effect of variations in pressure, yand underwater sea life distribution.

It will be apparent, therefore, that there has been described and illustrated a combined toy and visual educational device which is fully capable of attaining the objects and advantages preliminarily set forth.

While three preferred embodiments of the invention have been disclosed for illustrative purposes, numerous modifications in design and arrangement of parts are possible within the scope of the following claims.

I claim:

1. In a Cartesian driving toy of the type characterized by a uid lled hermetically scalable hollow chamber, a manually operable pressure control operatively connected to said chamber for selectively varying the fluid pressure within the chamber and a Cartesian diver element within the chamber and capable of vertical movement in response to fluid pressure fluctuations produced by the pressure control, the improvement which comprises:

a plurality of inclined baiiie-like partitions vertically sp-aced at depth intervals throughout the interior of the chamber and rigidly secured thereto, thereby defining a series of vertically spaced zones;

each of said partitions being so shaped so las to provide at least one opening to permit passage of the diver element to adjacent depth zones, said openings being so positioned relative to those in partitions at the adjoining level that passage of the diver element between successive zones lies only along a path requiring :a component of horizontal displacement of the diver element within each zone, the interior of the chamber thus providing a maze-like route for the diver element to negotiate;

such horizontal displacement being produced when manually controlled pressure fluctuations bring the diver element into contact with one of said inclined partitions, continued application of a depth-changing pressure signal maintaining the diver element in contact with said partition, and said partition acting as a camllike guide to produce a horizontal displacement of the diver element along its inclined surface toward the opening communicating with the adjacent zone.

2. The toy of claim 1, wherein said partitions each comprise a series of Z-shaped convolutions so oriented relative to similar convolutions in partitions at adjacent levels that Ia series of carefully timed depth-changing pressure reversals must be manually produced while the diver element is in each zone of the chamber to guide the diver element through that zone toward the desired communicating opening.

3. In a Cartesian diving toy of the type characterized by a fluid filled hermetieally scalable hollow chamber, a manually operable pressure control operatively connected to said chamber for selectively varying the uid pressure lwithin the chamber, and a Cartesian diver element within the chamber and capable of vertical movement in response to iluid pressure iluctuations produced by the pressure control, the improvement wherein:

said chamber comprises a continuous conduit in the form of a loop having a plurality of inclined Z- shaped bends along its length, the relationship of the inclination of the walls of said conduit to the location of the vertices of said bends being such that the loop can be traversed by the diver element only by a series of carefully timed and controlled reversals of fluid pressure by the manually operable pressure control to produce both horizontal and vertical displacement of the diver element;

such horizontal displacement being produced when manually controlled pressure fluctuations bring the diver element into contact with an inclined Wall of said conduit, continued application of a depth-changing pressure signal maintaining the diver element in contact with said conduit wall, said wall acting as a cam-like guide to produce a horizontal displacement of the diver element as it moves along said inclined Wall until it reaches the next bend in said loop, at which point appropriate pressure fluctuations would be selectively manually produced to permit further travel of the diver element along said conduit.

References Cited UNITED STATES PATENTS 2,525,232 l0/l950 McGaughy 46-92 X 2,779,131 l/1957 Scheithauer 46-92 3,299,419 1/l966 Fry 46-92 FOREIGN PATENTS 241,848 10/1925 Great Britain. 247,125 2/ 1926 Great Britain. 126,055 9/1949 Sweden.

F. BARRY SHAY, Prima/y Examiner.

RICHARD C. PINKHAM, ANTON O. OECHSLE,

LOUIS I. BOVASSO, Examiners.

T. ZACK, Assistant Examiner. 

1. IN A CARTESIAN DRIVING TOY OF THE TYPE CHARACTERIZED BY A FLUID FILLED HERMETICALLY SEALABLE HOLLOW CHAMBER, A MANUALLY OPERABLE PRESSURE CONTROL OPERATIVELY CONNECTED TO SAID CHAMBER FOR SELECTIVELY VARYING THE FLUID PRESSURE WITHIN THE CHAMBER AND A CARTESIAN DIVER ELEMENT WITHIN THE CHAMBER AND CAPABLE OF VERTICAL MOVEMENT IN RESPONSE TO FLUID PRESSURE FLUCTUATIONS PRODUCED BY THE PRESSURE CONTROL, THE IMPROVEMENT WHICH COMPRISES: A PLURALITY OF INCLINED BAFFLE-LIKE PARTITIONS VERTICALLY SPACED AT DEPTH INTERVALS THROUGHOUT THE INTERIOR OF THE CHAMBER AND RIGIDLY SECURED THERETO, THEREBY DEFINING A SERIES OF VERTICALLY SPACED ZONES; EACH OF SAID PARTITIONS BEING SO SHAPED SO AS TO PROVIDE AT LEAST ONE OPENING TO PERMIT PASSAGE OF THE DIVER ELEMENT TO ADJACENT DEPTH ZONES, SAID OPENINGS BEING SO POSITIONED RELATIVE TO THOSE IN PARTITIONS AT THE ADJOINING LEVEL THAT PASSAGE OF THE DIVER ELEMENT BETWEEN SUCCESSIVE ZONES LIES ONLY ALONG A PATH REQUIRING A COMPONENT OF HORIZONTAL DISPLACEMENT OF THE DIVER ELEMENT WITHIN EACH ZONE, THE INTERIOR OF THE CHAMBER THUS PROVIDING A MAZE-LIKE ROUTE FOR THE DIVER ELEMENT TO NEGOTIATE; SUCH HORIZONTAL DISPLACEMENT BEING PRODUCED WHEN MANUALLY CONTROLLED PRESSURE FLUCTUATIONS BRING THE DIVER ELEMENT INTO CONTACT WITH ONE OF SAID INCLINED PARTI- 